Conventionally, a glass plate (in the present description and claims, the “glass plate” denotes, for example, a glass plate used in a flat panel display (FPD), such as a liquid crystal panel, a plasma panel, or an organic EL panel) used in a liquid crystal display or the like is produced from a glass plate (mother glass) having such a size that a plurality of glass plates each having a predetermined size can be produced.
To protect the surface of the glass plate from cullet generated during process steps, particles generated as a result of processes, or the like, a method of attaching a protective sheet to the surface of the glass plate is generally adopted. The thickness of such a glass plate is about 0.7 mm.
The glass plate is conveyed in a lateral state, that is, a horizontal state and cut to have a predetermined size by a plurality of process steps. Then, cut end edges of the glass plate are subjected to beveling, such as grinding or polishing. With this, a glass plate product having a predetermined strength is produced.
One prior art for conveying this type of glass plate is that: a plate member is sandwiched between a lower endless belt and an upper endless belt in an end surface processing machine; a lower surface of a lower moving portion of the upper endless belt is pressed against an upper surface of an upper moving portion of the lower endless belt; and the upper endless belt and the lower endless belt are moved at the same speed (see PTL 1, for example).
Another prior art is that a glass plate is sandwiched and transferred by endless conveyor belts (see PTL 2, for example). Yet another prior art is that glass plate sandwiching members are provided at upper and lower opposing surfaces of two pairs of upper and lower endless rotating chains, and a glass plate is sandwiched and transferred by the glass plate sandwiching members (see PTL 3, for example).